ISO15DWG4 RS422/RS485 Digital Isolator Equivalent & Substitute Parts

Part Overview

The ISO15DWG4 is a RS422/RS485 digital isolator manufactured by Texas Instruments, featuring 2500Vrms isolation voltage, 3-channel configuration, and 1Mbps data rate in a 16-SOIC package. The part is currently obsolete, necessitating identification of functionally equivalent alternatives for ongoing design support and procurement.

Substiute Parts

ISO15DWG4

Texas InstrumentsIn Stock: 40389ISO15DWG4 Datasheet

Current PartRFQ

ISO15DW

Texas InstrumentsIn Stock: 1178ISO15DW Datasheet

MFR RecommendedRFQ

ISO15DWR

Texas InstrumentsIn Stock: 4308ISO15DWR Datasheet

MFR RecommendedRFQ

MAX14945EWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1183MAX14945EWE+ Datasheet

MFR RecommendedRFQ

MAX14945EWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1107MAX14945EWE+T Datasheet

MFR RecommendedRFQ

MAX14948EWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 27967MAX14948EWE+T Datasheet

MFR RecommendedRFQ

MAX14949EWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1268MAX14949EWE+ Datasheet

MFR RecommendedRFQ

MAX14949EWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 3442MAX14949EWE+T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility is determined by the following critical parameters:

• Package Compatibility: All substitute parts must use 16-SOIC (0.295", 7.50mm Width) surface mount package
• Channel Configuration: 3-channel, 2/1 unidirectional topology required
• Isolation Technology: Capacitive coupling technology
• Operating Temperature Range: -40°C ~ 85°C minimum
• RoHS Compliance: ROHS3 Compliant status

Substitute parts are grouped into two categories based on isolation voltage and data rate performance:

Category A - Direct Functional Equivalents (ISO15DW, ISO15DWR): Texas Instruments parts maintaining identical 2500Vrms isolation voltage and 1Mbps data rate specifications.

Category B - Enhanced Performance Alternatives (MAX14945EWE+, MAX14945EWE+T, MAX14948EWE+T, MAX14949EWE+, MAX14949EWE+T): Analog Devices/Maxim Integrated parts offering higher isolation voltage (2750Vrms or 5000Vrms) and enhanced common mode transient immunity (35kV/µs typical), with reduced data rate (500kbps) and broader supply voltage ranges.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Identical Specifications)

ISO15DW and ISO15DWR are direct functional equivalents to ISO15DWG4. Both maintain 2500Vrms isolation voltage, 1Mbps data rate, and identical channel configuration. ISO15DWR is recommended as the primary choice due to active product status and higher current inventory (4202 pcs). ISO15DW remains available as a secondary option with Last Time Buy status.

For Enhanced Isolation Performance

MAX14948EWE+T and MAX14949EWE+ / MAX14949EWE+T provide 5000Vrms isolation voltage, doubling the isolation capability of the original part. These are suitable for applications requiring higher isolation margins. MAX14948EWE+T offers the highest inventory availability (27925 pcs) and includes specified propagation delay and rise/fall time parameters. MAX14949 variants provide equivalent isolation performance with broader supply voltage compatibility.

For Moderate Isolation Enhancement

MAX14945EWE+ and MAX14945EWE+T offer 2750Vrms isolation voltage with 35kV/µs common mode transient immunity, providing a middle-ground option between the original specification and maximum isolation alternatives. These parts support broader supply voltage ranges (1.71V ~ 5.5V) compared to the original 3.15V ~ 3.6V specification.

Packaging and Compliance Considerations

All substitute parts are ROHS3 compliant and use identical 16-SOIC surface mount packaging. Maxim Integrated parts feature MSL 1 (Unlimited) moisture sensitivity rating compared to MSL 2 (1 Year) for Texas Instruments parts, providing improved handling flexibility. Packaging variants (Tube, Tape & Reel, Cut Tape) are available across the substitute portfolio to match procurement requirements.

Frequently Asked Questions (FAQ)

Q: Can MAX14945 or MAX14948/MAX14949 parts directly replace ISO15DWG4 in existing designs?

A: Yes, all substitute parts maintain identical 16-SOIC package geometry, 3-channel 2/1 unidirectional configuration, and -40°C ~ 85°C operating temperature range. However, designs operating at the maximum 1Mbps data rate of ISO15DWG4 must account for the 500kbps maximum data rate of Maxim alternatives. Supply voltage compatibility must be verified; ISO15DW and ISO15DWR require 3.15V ~ 3.6V, while Maxim parts support broader ranges.

Q: What is the difference between ISO15DW and ISO15DWR?

A: Both parts are functionally identical with 2500Vrms isolation and 1Mbps data rate. The primary difference is packaging: ISO15DW is supplied in Tube format with Last Time Buy status, while ISO15DWR is supplied in Cut Tape & Digi-Reel format with Active product status and higher inventory availability (4202 pcs vs. 1168 pcs).

Q: Why do Maxim parts have lower data rates (500kbps vs. 1Mbps)?

A: The MAX14945, MAX14948, and MAX14949 families are designed with enhanced isolation voltage and common mode transient immunity specifications, which result in lower maximum data rates. Selection between 1Mbps (Texas Instruments) and 500kbps (Maxim) options depends on application bandwidth requirements.

Q: Are there supply voltage compatibility issues when substituting with Maxim parts?

A: ISO15DW and ISO15DWR require 3.15V ~ 3.6V supply voltage. MAX14945 supports 1.71V ~ 5.5V and 4.5V ~ 5.5V ranges, while MAX14948 and MAX14949 support 1.71V ~ 5.5V / 4.5V ~ 5.5V and 3V ~ 5.5V / 4.5V ~ 5.5V respectively. Designs using 3.3V or 5V supplies are compatible with all alternatives; designs using narrower voltage ranges must verify Maxim part compatibility.

Q: What is the significance of MSL rating differences?

A: ISO15DWG4, ISO15DW, and ISO15DWR have MSL 2 (1 Year) ratings, requiring storage in controlled humidity environments and baking before reflow if shelf life exceeds one year. Maxim parts feature MSL 1 (Unlimited) ratings, eliminating moisture sensitivity handling requirements and providing greater procurement flexibility for long-term inventory management.

Q: Which substitute part offers the best overall compatibility?

A: ISO15DWR provides the closest functional match with Active product status, highest inventory, and identical electrical specifications. For applications requiring enhanced isolation performance, MAX14948EWE+T offers the highest inventory availability (27925 pcs) with 5000Vrms isolation and specified timing parameters.